Patent attributes
An image forming apparatus is provided with a photoreceptor drum which includes a cylindrical drum whose surface is coated with a photosensitive layer, and a rear-side drum flange section; and a developer. A coupling section at which the photoreceptor drum is attached to or detached from an image forming apparatus main body includes an input section and an apparatus output section. The input section is includes an internal gear having teeth of an involute curve formed in an inner surface of the rear-side flange section and receives rotation driving force from the image forming apparatus main body. The apparatus output section is composed of an external gear having teeth in the same shape and in the number as the internal gear, and outputs the rotation driving force from the image forming apparatus main body to the input section.